Nissan Repair: Brakes on d21 pickup, brake master cylinder, rubber hoses

Question
I recently replaced every part of the brake system ( pads, calipers, master cylinder, hard lines, and rubber hoses, fluid ( gallons), wheel cylinders, everything except the brake booster and load control valve. I have bled the whole system repeatedly. I only have brake pedal pressure if I pump the pedal very fast and hold it but when I let go and try again there is nothing there. What am I missing, my local dealer will not help with tech ? only if I bring it there to him then he will only do it. Can't drive it so I can't get it there to him. Can you help me out?

Answer
there is a leak in your system somewhere.  try bleeding your lines onces again and if thats the case, check your vacuum lines around  your brake booster, if thats fine, then it has to be your brake master cylinder.  my first bet would be on bleeding your breaks one more time.  make sure you have plenty of fluid in your lines while bleeding.  when replacing all of your brake system, you allow a lot of oxygen into your lines and its a pain to get out.  also check for leaks at the wheel cylinders and inside the hub.  you maybe have a fitting loose.  good luck.